Circuit-controlling system.



No. 793,513. PATENTED JUNE 27, 1905.

A. O. EASTWOOD.

CIRCUIT CONTROLLING SYSTEM.

APPLICATION FILED 1120.19, 1904.

V a SHEBTSSHEET 1.

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PATENTED JUNE 27, 1905.

A. G. EASTWOOD.

CIRCUIT CONTROLLING SYSTEM.

APPLICATION FILED DBO.19, 1904.

3 SHEETS-SHEET 2.

fifihaysw Alllllll "Inn" No; 798,513. PATENTED JUNE 27, 1905.

A. O. EASTWOOD.

UNITED STATES Patented June 27, 1905.

AR"HUR C. EASTWOOD, OFOLEVELAND, OHIO.

CIRCUIT-CONTROLLING SYSTEM.

SPECIFICATION forming part of Letters Patent No. 793,513, dated June 27,1905.

Application filed December 19, 1904:. Serial No. 237,435-

To all whmn (it 717,04 concern:

Be it known that I, ARTHUR O. EASTWOOD, acitizen of the UnitedStates,residing in Cleveland, Ohio, have invented certain ImprovementsinCircuit-ControllingSystems,of which the following is a specification.

One object of my invention is to provide a system including apparatuswhich will automatically open an electric circuit when the current-flowtherein reaches or exceeds apredetermined amount or when the voltage ofsaid circuit drops to or below a predetermined minimum. It is alsodesired that the system shall include apparatus which may be actuated atwill from a distance for either opening or closing the circuit.

Another object of the invention is to provide a system by means of whichthe armature of a motor may be brought to a quick stop from any of anumber of points remote from the motor-controller.

The invention further embraces means whereby the armature-circuit ofthemotor will be automatically opened upon the failure of the voltage ofthe supply-circuit and means whereby the system is rendered inoperativeuntil the handle or equivalent part of the operating-controller isreturned to its oil? or normal starting position.

These objects 1 attain as hereinafter set forth, reference being bad tothe accompanying drawings, in which- Figure 1 is a diagrammatic view ofone combination of apparatus comprising my improved system, showing itas applied to the control of a series motor. Fig. 2 is a diagrammaticview showing my system as applied to the control of a shunt-motor andincluding a hand-operated controller and apparatus for quickly stoppingthe motor, and Fig. 3 is a diagrammatic view showing my system asapplied to the control of acompoundwound motor and including areversing-controller.

One application of my invention is found in connection withconveying-bridges in which the driving-motors are located at one end ofthe bridge structure and operatively connected, by means of cables, tohoisting and conveying apparatus mounted on a trolley arranged to travelupon the bridge, the operator riding on the trolley and therefromcontrolling the speed and direction of operation of the driving-motors.

To obviate the necessity for a large number of heavy connecting-wiresupon the bridge between the controller on the trolley and the stationarymotors, magnetically-operated controlling devices are usually employed,which, together with acontrolling resistance, are usually mountedadjacent to the driving-motors in the manner shown in my United StatesPatent No. 770,630, granted September 20, 1904. With such an arrangementof apparatus it is only necessary to run wires of relatively smallsection upon the bridge, and these, together with a smalloperating-controller on the trolley, provide the means whereby thenecessary connections may be made to the magnet-coils of themagnetically-operated switches controlling the motor or motors.

For the same reasons as above noted the main circuit-breaker is usuallyplaced adjacent to the motors, so that it frequently happens that theopening of said breaker by reason of an overload leaves the operator onthe trolley without power and with no means of conveniently resettingthe circuit breaker other than to climb down to the motor-house or towait until the resetting is done by some one else. This conditionusually involves considerable inconvenience and loss of time. By myimproved system the possibility of this trouble is removed, since theoperator is provided with means on the trolley whereby he canconveniently and quickly reset the circuit-breaker at will irrespectiveof the position of the trolley up )n the bridge. Means is also providedwhereby the operator can instantly open the main circuit from his position upon the trolley, and so cut off the current in case of accident orinjury to the cables or other portions of the machine.

In various current-controlling systems em-' ploying magnetically-o'ierated switches these latter are designed to operate within a certainrange of applied voltage. If, however, the

voltage of the supply-circuit drops below a certain minimum value, theaction of the switches becomes erratic, so that for the protection bothof the controller and of the motors it is desirable in order to securereliable operation of the apparatus that the circuit be automaticallyopened when this critical voltage is reached and, moreover, bemaintained open until the voltage of, the siuiplycircuit has again risento its proper value.

Hitherto apparatus has been provided which upon the failure of thevoltage of the supplycircuit permitted a controller or rheostat arm tomove to its off position under the action of a weight or spring. Thesedevices have, however, proved unreliable by reason of the frictionresulting from burned or pitted contacts, so that frequently it wasfound that when the voltage failed the contact-arm would stick at someintermediate point,causing burning out of the armature or of theresistance I upon the restoration of the current. Frequentl y also thesticking above noted resulted in serious delay in cases where a numberof meters of large size were operated on the same circuit, since if themain circuit breaker or fuse opened and the contact-arm of one of theCOI'llllOllM'S failed to return to the off position practically a shortcircuit was created, and all of the motors on the circuit had to remainidle till the defective instrument was found and the trouble corrected.

By my invention the above-noted objectionable conditions are obviated,and while in the figures 1 have shown said. invention employed tooperate various forms of electric motors these may be replaced by otherforms of current-actuated apparatus without departing therefrom.

Referring to Fig. 1, A represents the armature of a series motor havinga field-winding F. S is a main switch controlling the curren tl'low fromthe supply-mains and has connected to one of its terminals one end ofthe fieldwinding F, while its second terminal is connected to the,armature A through the coil of an overload controlling switch E and amagnetically-opcrated switch S. The switch is provided with means, as aweights, whereby it is maintained in its open position as long as itsactuating-coil is deenergized. The coil 0 of the switch E is providedwith a movable core 0, placed so as to engage and operate a pivotedblade 0 under certain conditions of current-flow in said coil. Saidblade normally connects a terminal in connection with the positive sideof switch S and any number of normally closed hand-operated switches b,7), and If, connected in series with each other and with one end of theactuating-coil a of the switch S. The opposite end of said coil isconnected to one end of an auxiliary switcha, designed to be closed by ametallic piece carried upon but insulated from the blade of switch S,whose second terminal is connected to the negative side of the mainswitch S through a bank of resistance R. That terminal of the auxiliaryswitch s to which the coil s is connected is also connected to oneterminal of each of any desired number of normally open switches c, c,and 0, whose second terminals are all connected together and to thenegative side of the main switch S.

When my invention is used in connection with a conveying-bridge and asystem such as indicated above, one each of the switches and c is placedupon the trolley, while the motor, together with switches S S and theoverload-controlling device E, are placed in a suitable inclosure uponthe bridge. If new it is desired to start the motor from the trolley,the main switch S is first closed, though it will be noted that suchclosing does not supply current to the motor, since the switch S isopen, as is also the circuit of its coil. The switches c and 7) areusually of the push-button type, and if the lirst of these be closedcurrent will flow from the positive side of the main switch S throughcoil 0, switch-bladew, switches b, and coil .s, thus energizing thelatter and causing closure of the switch S. Such closure of this latterswitch permits current to How to the motor through the variouscontrolling mechanism, which is omitted from Fig. 1 for the sake ofclcarness.

The closing of the switch S closes the auxiliary switch s, therebyrendering the current-flow through the coil a independent of theswitches 0, since there is a complete circuit from the main switch Sthrough switches 71, coil s, auxiliary switch and resistance it to thenegative terminal of said main switch. Said resistance R serves to cutdown,. and hence economize, the current-fl ow through the coil s, suchcutting down of the current being allowable in view of the fact thatmuch less current is required to hold the switch S in a closed positionthan is required to bring it to such position. if it be desired to cutoff the current-supply to the motor, one of the switches 7) may beoperated, with the result that the circuit including the-coil x isbroken and the switch S is permitted to open, thereby breaking the mainmotor-circuit.

Should an overload occur on the motor, so that the currei'it-l'lowthereto rises above a pre determined maximum, the core w isdrawn intothe coile and made to strike and raise the. switch-blade c, with theresult that the circuit of the coil .9 is opened, thereby permittii'igthe switch S to open under the action of its weight .s, as before.

Should the voltage of the suppl y-circuit fall below a predeterminedminimum, the weight .v will overcome the effect of the coil upon theplunger of the switch S and said switch will open, thus opening the mainmotor-circuit. The restoration or rise of voltage in the circuit aftersuch opening cannot cause the switch S to close, since, as before noted,its coil x is open-circuited by reason of the open position of theauxiliary switchx and the switches c. The closure of any of these latterIIO switches will, however, complete the circuit through the coil 5, asbefore noted, causing the switch S to close. It will be understood thatthe switches c and b can be placed at any widely-separated points, sothat the operation of the switch S, and consequently the operation ofthe motor, may be controlled from a distance.

In that embodiment of my invention shown in Fig. 2 I have illustrated ahand-operated controller D as connected in circuit with the armature andfield winding of a motor which is of the shunt type, the speed of suchmotor being varied by varying the amount of resistance in its armatureand field circuits. The controller is provided with a movable arm (Z,having a contact-piece designed to electrically connect with each otherthe various segments, of which there are four sets in thepresentinstance, arranged concentrically with said arm. One of thesegments Cl is continuous throughout its length, which is equal to there through which the controller-arm is to be operated, and ispermanently connected to one pole of the main switch S. Upon a secondare are two segments (Z and (.Z", insulated from each other, the shorterof these being so placed as to be engaged by the contact-arm of thecontroller as soon as it is moved from its off position, and therebyelectrically connected with the segment (Z. This segment (Z is connectedto oneend of the coil 8 of the'electromagnetic switch S and also to theauxiliary switch .9, operated by said first switch. The

second terminal of the switch 8 is connected above-mentioned segmentsincludes two series of segments lyingalong difl'erent arcs or lines, thefirst of these series (1 having connected between them the varioussections of a bank of armature resistance R and being so placed as to beengaged by the contact-piece of the arm (Z just as this latter isleaving the segment (1". The last one of the segments d is of greaterlength than the others, being extended so as to remain in engagementwith the contact-arm of the controller as this latter is moved throughthe latter part of its path of motion and being in connection with oneterminal of the armature A.

The second series of segments (Z includes a relatively longsectionplaced to be engaged by the contact-arm (fl as soon as this ismoved from its of? position and extending to a point beyond a straightline connecting the pivot of the contact-arm and the end of the long oneof the segmentsd" adjacent to the resistance R. The others of thesegments (.Z have connected between them the sections of a bank of fieldresistance R one end of which with the long one of the segments (Z isconnected to one end of the shunt field-winding f, whose opposite end isconnected to the positive terminal of the main switch SQ As in the caseof the arrangement of parts shown in Fig. 1, I providea series ofswitches 72?) b interposed between the coil 8 of the switch S and thepositive terminal of switch S. I also provide a switch S and a bank ofresistance R in series therewith connected between the terminals of thearmatureA and employ a locking-bar L, extending between the blades ofthe switches S and S whereby said switches are kept from both being in aclosed position at the same time. The actuatiug-coil x 01 the switch Sis connected directly across the armature-terminals.

When the controller-arm (Z is in its ofi position, as shown, the circuitof the armature A is open, as are also the circuits of the coil 8,

switch S, and of the shunt field-windingf of the motor, although if ithe desired that said winding shall not be open when the arm B is in thisposition this can be accomplished by extending the segments '(Z and (Zso that they will be connected by the said contact-armwhen in said offposition.

1f the controller-arm d be moved in a clockwise direction from theposition shown, the circuit of the coil 8 will be closed as soon as saidarm connects the segments (1 and 612. Even though continued motion ofthe arm (Z causes its contacts to break engagementwith the segment (Zthe circuit of the coil .9 is not open, since, as in the arrangementshown in Fig. 1, the auxiliary switch a has been closed by the closingof switch S, thus permittingcurrent to flow from the positive side ofswitch S through switches 7), Z), and b coil s, auxiliary switch sresistance R, segments 7) and (Z, and so to the negative terminal of themain switch.

hen the arm (Z engages the first of thesegments d", the circuit throughthe armature of the motor is completed and said armature should begin torevolve. As the controller-arm is moved farther forward the resistance Ris gradually cut out, with a consequent increase in the armature speed,and when said arm by its continued motion cuts into circuit with theshunt-field all of the resistance R the armature is brought up to itsfull speed. In the meantime the coil s of switch S is excited by theelectromotive force generated by the armature A and though tending toclose is prevented from doing so by the IOcking-barL and the switch S.Consequently if the motor be running at full speed (or at anintermediate speed) and the voltage of the supply-circuit should fail orfall below a predetermined minimum the coil of switch S will bedeenergized, so as to cause said switch'to open and cut ofi the armatureA from the supply-mains. Switch S is now closed by the action of itscoil, and the motor acting as a self-excited generator forces currentthrough the resistance R, thus quickly bringing the armature to rest.

As before noted, when the switch S has once been opened it will notclose upon the restoration of the current to the su pray-mains, it beingnecessary in the system shown in Fig. 2 to return the controller-arm (Zto its starting position, so as to electrically connect the segment (1and d, after which the motor may he started as before. I t any of theswitches 7) be opened while the motor is in operation, the circuit ofthe coil 8 will be broken and the braking-switch S will be automaticallyoperated, as above noted, to bring the armature to a quick stop. Asbefore, it is now necessary to return the controller-arm (Z to itsstarting position before the motor can again be set in operation.Similarly when the arm 7) is moved by hand to its oil position thecircuit of the coil .9 is opened and the armature A is quickly broughtto rest, it being noted in any case that the opening of thearmaturecircuit upon the failure of the line voltage or upon theoperation of one of the switches 7) is accomplished by the switch 8' anddoes not depend upon the return of the controllerarm d to its offposition, as is the case in devices of this nature at present known tothe art. Said switch is positively opened by the action of its weight orequivalent part, which has only to overcome the slight friction in thebearings of the switch and may therefore be depended upon to open it.

In Fig. 3 is illustrated another application of my invention, showing itas applied to a system including a compound-wound motor operated by areversing-controller of the drum type, the speed of the motor beingvaried by varying the amount of the resistance R in itsarmature-circuit. While with this arrangement 1 have illustrated theoverload-controlling device E as forming part of the system, it will beunderstood that it may be omitted, if desired, as in the case of Fig. 2,without all'ccting the operation of the other parts thereof. In thedrum-controllerjl (shownin Fig. 3) a linger (,Z is connected to one endof the coil a, while the finger (Z like the segment (Z of Fig. 2, isconnected to one terminal of the auxiliary switch N the operation ofswitch S being the same as previously described.

I claim as my invention 1. The combination of a current-actuated device,an electromagnetic switch in circuit therewith, and two auxiliarycircuits, one including a normally open switch independent of theelectromagnetic switch and the other including an auxiliary switchoperated by said electromagnetic switch, each of the auxiliary circuitsbeing connected to complete the circuit of the coil of saidelectromagnetic switch independently of the other, substantially asdescribed.

2. The combination of a current-actuated device, an electromagneticswitch in circuit therewith, and two auxiliary circuits, one in cludinga normally open switch imlepemlent of the electromagnetic switch and theother including an auxiliary switch operated bysaid electromagneticswitch, both circuits being connected to complete the circuit throughthe coil of the electromagnetic switch indepcmdently of each other, anda bank of resistance in circuit with said auxiliary switch,substantially as described.

3. The combination of a current-actuated device, an electromagneticswitch in circuit therewith, and two auxiliary circuits for connectingthe coil of said switch with a source of current-supply, a bank ofresistance inonc of said auxiliary circuits, an auxiliary switchcontrolled by said electromagnetic switch, means for making and thenbreaking the first auxiliary circuit, and means for making the secondauxiliary circuit before said lirst auxiliary circuit is opened,substantially as described.

4. The combination of a current-actuated device, an electromagneticswitch in circuit therewith, and two auxiliary circuits, one including anormally open switch independent of the electromagnetic switch and theother including an auxiliary switch operated by said electromagneticswitch, both circuits being connected to complete the circuit throughthe coil of said electromagnetic switch, with an automatic switch alsoconnected to said coil having means for open-circuiting said coil whenthe current'['low through the currentactuated device exceeds apredetermined amount, substantially as described.

5. The combination of a current-actuated device, an electromagneticswitch in circuit therewith, and two auxiliary circuits, one including anormally open switch independent of the electromagnetic switch and theother including an auxiliary switch operated by said electromagneticswitch, both circuits being arranged to. complete the circuit throughthe coil of said electromagnetic switch, with an automaticoverload-switch and a hand-operatcdswitch also in circuit with saidcoil, substantially as described.

6. The combination of a current-actuated device, an electromagneticswitch in circuit therewith, means tending to open said switch, anauxiliary switch constructed to be closed by the closing of theelectromagnetic switch, and a hand-operated switch in shunt to theauxiliary switch, the coil of the electromagnetic switch being connectedboth to the auxiliary and to the hand-operated switches, substantiallyas described.

7. A system having a main circuit including a current-actuated device, awinding and an electromagnetic switch, an auxiliary switch actuated bythe winding and a hand-operated switch, both normally closed and incircuit with Lil the coil of the electromagnetic switch, with twocircuits in shunt to each other and both including means for completingthe circuit.

through said coil, substantially as described.

8. A system including an electromagnetic switch and a current-actuateddevice, means for causing closing of said switch at will, and anauxiliary switch having a member operated by the electromagnetic switchfor maintaining the circuit through the coil thereof independently ofand after the operation of said closing means, substantially asdescribed.

9. A system including a current-actuated device, a main switch therefor,hand-operated switches independent of said main switch connected tocause opening and others for causing closing of said main switch, andadditional means for opening said main switch, both when the voltage ofthe supply-circuit falls below a predetermined minimum and when the current-flow to the current-actuated device rises above a predeterminedmaximum, substantially as described.

10. A system including a motor, acontroller for the same, an automaticswitch in circuit with the motor-armature, said controller including acontact whereby the coil of the switch is supplied with current beforethe circuit of the motor-armature is completed, and means formaintaining the current flow through said coil independently of saidcontact after the switch is closed, substantially as described.

11. Asystemincludinga motor, acontroller for the same, an automaticswitch in circuit with the motor-armature, said controller including acontact whereby the coil of the switch is supplied with current beforethe circuit of the motor-armature is completed,a normally closedhand-operated switch or switches also in circuit with the coil, and acircuit in shunt to the controller-contact whereby the said coil may beenergized independently of said contact, substantially as described.

12. The combination of a motor, a controller therefor and an automaticswitch, the coil of said switch having two branch circuits whereby itmay be connected to a source of current-supply, both of said circuitspassing through said controller, substantially as described.

13. The combination of a motor, a control ler therefor and an automaticswitch, the coil of said switch having two branch circuits whereby itmay be connected to a source of current-supply, both of said circuitspassing through said controller, with means actuated by said switch formaintaining one of the circuits after the other has been opened in thecontroller, substantially as described.

1 1. The combination of a motor, a controller therefor, an automaticswitch in circuit with the motor-armature, and an auxiliary switchactuated by said automatic switch and having a terminal connected to thecoil thereof, said controller including two contacts respectively incircuit with said coil of the automatic switch and the secondterminal-of the auxiliary switch, substantially as described.

15. A motor, a controller therefor, means independent of the controllerfor opening the armature-circuit of the motor when the voltage of thesupply-circuitfalls to a predetermined point, and means, including anelectromagnetic main switch and means for keeping the winding of saidswitch open-circuited, for preventing the restoration of current to saidarmature-circuit until the controller has been operated to its startingposition, substantially as described.

16. A motor, a controller therefor, means independent of the controllerfor opening the armature-circuit of the motor when the voltage of thesupply-circuit falls to a predetermined point, including an automaticswitch, a contact connected thereto and so placed in the controller asto be supplied with current only when said controller is in its startingposition, with means for supplying current to the winding of the switchafter the controller has been operated past said starting position,

substantially as described.

17. A motor, a controller therefor, including a contact placed to be incircuit only when the controller is in its starting position, and asecond contact placed to be in circuit after the controller has beenoperated from said position, an automatic switch in the mainmotorcircuit, an auxiliary switch operated by the automatic switch andin circuit with the coil thereof, said automatic switch and the coilbeing respectively connected to said two contacts of the controller,substantially as described.

18. The combination of a motor, an electromagnetic switch in circuittherewith, and two auxiliary circuits, one including a normally openswitch and the other including an auxiliary switch operated by saidelectromagnetic switch, both of the auxiliary circuits being connectedto complete the circuit of the coil of the electromagnetic switch, aswitch for short-circuiting the armature and means for preventing saidlatter switch and the electromagnetic switch both being closed at thesame time, substantially as described.

19. A system including an electromagnetic switch and a current-actuateddevice, means for causing closing of said switch at will, and means formaintaining the circuit through the coil of said electromagnetic switchindependently of and after the operation of said closing means, with anautomatic switch connected to short-circuit the current-actuated deviceand a locking-bar extending between said automatic switch and theelectromagnetic switch, for preventing both of said switches being in aclosed position at the same time, substantially as described.

20. The combination of an electromagnetic IlO switch, an auxiliaryswitch controlled thereby said terminal of the auxiliary switch,substarv having both its terminals connected to the tially as described.

same current-supply main, a normally open In testimony whereo'fl havesigned my name controlling switch or switches interposed beto thisspecification in the presence ol two sub 5 tween said current-main andone of said terscribing witnesses.

n'iinals, with a normally closed controlling V 1 1! r switch orswitches, said latter switch or ARUIUR switches and the coil of theelectromagnetic \Vitnesses: switch being interposed in the connectionbe- E. R. LOUGHERY,

1O tween the second current-supply main and the Jos. H. KLEIN.

